Steering System Troubles

The condition of the steering system has a profound effect not only on the performance of the tractor or automobile, but also on road and operation safety.

It is prohibited to operate a tractor or automobile suffering from the following steering troubles: hard steering, excessive play in the steering system, excessive wear of steering system components, loose joints and fasteners, and damaged cotter pins.

Even slight binding of the steering gear or linkage may result in an accident, for this condition is very tiring to the driver. Hard steering in conditions of heavy traffic and high running speeds is conductive to collisions and run-overs. If hard steering occurs just after the steering system has been worked on, the trouble is probably due to excessively tight adjustments in the steering gear or linkage. If it occurs at other times, hard steering could be due to excessive friction in the steering gear or linkage or at the ball joints, bent steering rods, or damaged steering worm bearings.

On a tractor or automobile with power steering, failure of the power steering gear will cause the steering system to change to mechanical steering. It will require greater steering effort to turn the steering wheel. When this happens, the power steering system and the pump should be checked and the cause of trouble revealed and corrected.

The steering linkage can be checked for binding by raising the front end of the tractor or automobile. Turn the steering wheel from left to right. If you feel any binding, disconnect the linkage from the steering arm. If this relieves the hard steering, the trouble is in the linkage. If hard steering is still a problem, the trouble is in the steering gear itself.

Damaged and badly worn components of the steering gear or linkage should be replaced, loose joints and fasteners tightened, and damaged or lacking cotter pins replaced.

Excessive play in the steering system shows up as a free movement of the steering wheel without corresponding movement of the front wheels. A small amount of free play, or tilt, is desirable, because it makes steering easier. But when the play is excessive, it can make steering harder. Excessive play may be due to loose wheel bearings, steering-rod ball joints, steering-box fasteners, steering arm, and steering knuckle arms, and excessive backlash between the steering worm and roller (sector). These conditions are corrected in the same order as they are listed here.

ADJUSTING THE FRONT WHEEL BEARINGS. Normal axial play in the taper roller bearings of the front wheels is around 0.2 mm. The wheel bearings can be checked for looseness by raising the front end of the tractor or automobile. Then grasp the wheel at the top and bottom. If you can wobble the wheel, there is looseness in the wheel bearings or ball joints. Have someone apply the brakes as you again try to rock the wheel. If applying the brakes eliminates the free play, the wheel bearings are loose. If the play is more than 0.5 mm, the bearings should be adjusted.

Before making adjustment, clean the hub cap and remove it from the hub. Remove the cotter pin and tighten the adjusting nut until the wheel is tight on its spindle. Then back off the nut to make the nearest pin slot in the nut register with the pin hole in the spindle. With the bearings adjusted properly, the wheel should be easy to turn without any appreciable free play.

ADJUSTING THE WORM-AND-ROLLER TYPE OF MANUAL STEERING GEAR. If the steering wheel play is more than recommended by the manufacturer, the steering system should be adjusted.

First adjust the ball joints of the steering linkage and the front wheel bearings. If the steering wheel play still remains a problem, check the taper roller bearings of the steering worm for looseness. To do this, disconnect steering gear connecting rod from steering arm and demesh steering worm from the roller by turning the steering wheel either way. Grasp the steering wheel and move it up and down. If the movement of the steering shaft is noticeable, tighten the steering worm bearings by removing some of the shims placed under steering box bottom cover. With the steering worm bearings adjusted properly, a force of 3 to 5 N (0.3 to 0.5 kgf) should be sufficient to turn the steering wheel.

Then set the roller at the center of the steering worm and check the backlash between them by rocking the steering arm. If the backlash is excessive, it should be adjusted.

The backlash between the roller and the steering worm should be adjusted as follows. Remove the steering gear, unscrew the lock nut of the adjusting screw, and remove tab washer. Adjust the backlash by screwing in the adjusting screw so as to have the backlash at its minimum with the roller set at the center of the steering worm. Lock the adjusting screw with the tab washer and lock nut and mount the steering gear in place.

ADJUSTING THE WORM-AND-SECTOR TYPE OF POWER STEERING GEAR. If it proves impossible to eliminate the excessive steering wheel play by adjusting the ball joints of the steering linkage, it is then necessary to adjust the backlash between steering worm and sector. The outer end of the steering worm is supported by the ball bearing press-fitted in adjusting eccentric bushing. As the centers of the outer and inner surfaces of the bushing do not coincide, turning the bushing in its bore in the steering box will change the position of the steering worm relative to the sector. To make such an adjustment, remove the radiator shell, disconnect the steering knuckle tie rods from the steering arm, and loosen the two bolts that hold the flange of the adjusting bushing to the steering box. Insert a wrench in the slot in the bushing flange and turn the bushing clockwise (facing the front of the tractor) until there is no backlash between the steering worm and the sector with the steering arm in the central position. Then turn the flange of the bushing 4 to 6 mm counterclockwise and tighten its fastening bolts.

Finally, start the engine and check the steering gear for binding by turning the steering wheel all the way from left to right and back.